Electronic devices have become smaller and lighter according to the development of technology and can have a variety of configurations. Accordingly, wearable devices that can be worn by a user have been developed. For example, smart watches or smart glasses have been developed. A smart watch refers to an embedded system wristwatch that generally has more advanced features than a typical watch. A smart glass refers to a wearable computer that is generally equipped with a head mounted display (HMD). The wearable devices can be classified into a standalone device and an interlocking device. A standalone device is equipped with a self input/output device, an arithmetic unit, a storage device, and a communication device, and can be used alone. An interlocking device refers to a device that can be used after being connected with a separate device such as a smart phone.
Since the wearable device is worn on a user, it is advantageous for obtaining a biosignal from the user. Thus, a wearable device including various sensors has been developed. For example, a smart watch may be provided with a glucose sensor or a blood pressure sensor. The wearable device can be equipped with various sensors, such as a biosensor, a motion sensor, a chemical sensor, a temperature sensor, and a position sensor. A biosensor refers to a device for measuring a state or concentration of an organic compound by using a function of a living organism. A motion sensor refers to a device for detecting a movement of the device. For example, the motion sensor can include a gyroscope or an acceleration sensor. A chemical sensor refers to a sensor targeting a chemical material for measurement. A temperature sensor refers to a device for measure a temperature. A position sensor refers to a device for measuring a position such as a ground positioning system (GPS).
However, sensors may have different accuracy according to adherency information provided by the user. Thus, sensors need to be in close contact with the body of the user's body. On the other hand, if a sensor is positioned too close to the user, the user may suffer from pressure and feel uncomfortable.